MEMS device and fabrication method of the same

Abstract

A microelectromechanical systems (MEMS) device includes a frame, an actuator formed on the same layer as the frame and connected to the frame to be capable of performing a relative motion with respect to the frame, and at least one stopper restricting a displacement of the actuator in a direction along the height of the actuator. The MEMS device is fabricated by bonding a second substrate to a first substrate, forming the frame and the actuator by partially removing the first substrate, and forming the at least one stopper by partially removing the second substrate.

1. A method of fabricating a microelectromechanical systems (MEMS) device, the method comprising:
 bonding a second substrate to a first substrate; 
 forming a frame and an actuator connected to the frame to be capable of performing a relative motion with respect to the frame by partially removing the first substrate; and 
 forming at least one stopper which restricts a displacement of the actuator in a direction along the height of the actuator by partially removing the second substrate, 
 wherein the forming of at least one stopper comprises forming an ascending restriction stopper which restricts an upward displacement of the actuator and a descending restriction stopper which restricts a downward displacement of the actuator. 
 
     
     
       2. The method of  claim 1 , wherein the first and second substrates are formed of silicon. 
     
     
       3. The method of  claim 1 , wherein the forming of an actuator comprises forming the actuator connected to the frame to be capable of pivoting with respect to the frame. 
     
     
       4. The method of  claim 1 , further comprising partially etching a lower surface of the second substrate before bonding the first substrate and the second substrate to allow an end portion of the at least one stopper to be separated from the first substrate. 
     
     
       5. The method of  claim 1 , further comprising partially etching an upper surface of the first substrate before bonding the first and second substrates to allow an end portion of the stopper to be separated from the first substrate. 
     
     
       6. The method of  claim 1 , wherein the forming of the actuator comprises:
 forming an external variable portion connected to the frame to be capable of pivoting about a first pivot axis with respect to the frame; and 
 forming an internal variable portion located inside the external variable portion to be capable of pivoting about a second pivot axis with respect to the external variable portion, the second pivot axis being perpendicular to the first pivot axis. 
 
     
     
       7. A method of fabricating a microelectromechanical systems (MEMS) device, the method comprising:
 bonding a second substrate to a first substrate; 
 forming a frame and an actuator connected to the frame to be capable of performing a relative motion with respect to the frame by partially removing the first substrate; 
 forming at least one stopper which restricts a displacement of the actuator in a direction along the height of the actuator by partially removing the second substrate; and 
 forming a stage fixed to the actuator by partially removing the second substrate. 
 
     
     
       8. The method of  claim 7 , further comprising partially etching a lower surface of the second substrate before bonding the first and second substrates to form a separation column provided between the actuator and the stage. 
     
     
       9. A method of fabricating a microelectromechanical systems (MEMS) device, the method comprising:
 bonding a second substrate to a first substrate; 
 forming a frame and an actuator connected to the frame to be capable of performing a relative motion with respect to the frame by partially removing the first substrate; 
 forming at least one stopper which restricts a displacement of the actuator in a direction along the height of the actuator by partially removing the second substrate; and 
 forming a drive coil wound around a peripheral portion of the actuator; and 
 arranging at least one magnet which forms a magnetic field that crosses current flowing in the drive coil. 
 
     
     
       10. The method of  claim 9 , wherein the forming of the drive coil comprises:
 forming at least one drive coil groove by etching a lower surface of the first substrate; and 
 depositing metal in the at least one drive coil groove.